Evolution of PVA gels prepared without crosslinking agents as a cell adhesive surface.

Physical parameters (such as crosslinking density, crystallinity and mechanical properties) have been found to largely affect cellular behavior on polymer scaffolds. This study demonstrated that transparent pure Poly (vinyl alcohol) hydrogels prepared via a freeze-thaw method can be made to support cell adhesion by controlling physical parameters such as concentration and the number of freeze-thaw cycles. For a given number of freeze-thaw cycles, (specifically 45), polymer concentration dependent structural and mechanical properties (such as tensile strength and stiffness) were correlated with cell adhesion. The maximum cell attachment occurred on the hydrogels with the greatest mechanical properties, crystallinity and crosslinking density. The hydrogel surfaces were more favorable to human dermal fibroblasts than human lens epithelial cells and retained their transparency as well as dimensional stability with only a small degree of swelling. Fibroblast laden hydrogels showed extensive alkaline phosphatase activity which confirmed their healthy proliferation and function. In this manner, this study suggests that transparent Poly (vinyl alcohol) hydrogels prepared by the freeze thaw method described here should be further studied for numerous tissue engineering applications.